Mating connector for the On Shore Technologies OSTNR series, example part number OSTNR161201
Link to the OSTNRXX1201:
OSTNRXX1201 Terminal Block Pluggable Header with Flange - On Shore Technology, Inc.
After you click the link you will see the **Mating Options Tab.
Now click the picture of the Connector on that page. You will get the mating connector information.
The mating connector is the OSTNL series. Example part number OSTNL161002. Link below.
OSTNLXX1051 Terminal Block Pluggable Spring Clamp with Flange - On Shore Technology, Inc.